Sinclair Transmits OFDM in Baltimore

BALTIMORE – Wednesday, March
27 was an auspicious day for the engineers at Sinclair in Balmer.

“This morning at 3:35 a.m. Eastern Time, we lit up the greater Baltimore/Washington
market with 800-plus kW ERP of DVB-T2 (OFDM) power,” Sinclair’s Mark Aitken wrote
to Mark Richer, president of the Advanced Television Systems Committee, which is
now at work on modernizing the broadcast television transmission standard. (Aitken is pictured at right in the forefront, with Mike Simon of Sinclair in the baseball hat; Acrodyne General Manager Andy Whiteside; and Stu Boughton of Acrodyne. Bill Soreth of Acrodyne also participated.)

For Aitken and others at Sinclair, the use of orthogonal frequency division multiplexing
in the United States is a long-held conviction. Sinclair and its chief David Smith
championed coded OFDM in the 1990s when the industry was preparing for the digital
transition. Smith was thinking of mobile reception capabilities back then, for which
COFDM was more suitable than eight-level vestigial sideband, or 8-VSB modulation.
The latter nonetheless won the endorsement of the ATSC and was adopted as the U.S.
transmission standard.

Sinclair has since doubled its TV station holdings to 112 stations in 61 markets,
covering nearly 30 percent of the U.S. population. The company also has continued
to advocate for mobile DTV, through the Open Mobile Video Coalition, and the Mobile500.
Last month, it was granted an experimental license by the Federal Communications
Commission to test DVB-T2—Europe’s mobile broadcast modulation standard based on
OFDM. (See Doug Lung’s “Details
on WNUV’s Experimental License to Test OFDM.”)

Sinclair’s inaugural DVB-T2 trial, conducted on its CW affiate signal, WNUV-TV, coincided with a call from the ATSC for proposals
on its so-called “next-generation” standard, version 3.0. It is clear to the ATSC
and the industry in general that the current configuration, which locks broadcasters
into using the MPEG-2 compression standard. MPEG-2 was sufficient for one high-definition
video signal within a 6 MHz channel (as far as CBS was concerned), or several, lower-res
multicast signals. It will not, however, accommodate 4K, or Ultra-HD, nor will the
standard in general support advanced features such as targeted advertising and multiplatform
distribution. (See “ATSC
Seeks Proposals for 3.0 Physical Layer.”)

Sinclair’s Aitken said the company would continue to participate in the ATSC’s standards
activities.

“Part of that participation may intersect needs to test and evaluate various systems
and technologies,” Aitken wrote. “I would like to extend to ATSC that Sinclair will
make every reasonable effort to provide support for its ongoing 3.0 activities by
providing for the use and access to the WNUV facility to support experimental needs….
We are committed to no specific standard or provider.”

“The configuration we operated gave us additional data band-width yielding 24.92
Mbps— 30 percent more than standard ATSC—with a [carrier-to-noise ratio] of 15.1
dB—same as ATSC—with an [modulation error ratio] of 33.5 dB… and shoulders well
within specs at -53dB or better at the output of the system,” Aitken said. “We were
running and receiving HD programming. For the record, it was received
over-the-air with a USB T2 receiver.”